Abstract:

  Background and Aim : Discoloration of dental composite resins is one of the most common reasons for replacement of composite restorations which may cause patient dissatisfaction and additional time and expenses for replacement. Tea is the most common drink among Iranians which is largely responsible for discoloration of composite restorations.The purpose of this study was to evaluate the effect of two types of tea (Iranian and imported) on discoloration of two commonly used microhybrid composite resins (FiltekZ250 and Point4).

  Materials and Methods : This experimental and invitro study was done on 30 specimens made from two composites FiltekZ250 and Point 4. The primary color measurement was done with spectrophotometer before immersing the samples in separate mediums. The specimens from each type of composites were randomly divided into three groups, each of which was then immersed in a different medium( Iranian tea, imported tea and distilled water). While immersed in the prepared mediums, the samples were stored in a 37˚c incubator for one week, after which time, the final color measurements were taken. Results were statistically analyzed with one way ANOVA test.

  Results: When exposed to the medium containing imported tea, the reported color changes in FiltekZ250 and Point 4 composites were measured to be: 11.84±1.71 , 12.29±4.10 and when exposed to the Iranian tea it was reported:7.87±0.85,5.98±2.12. Both composite resins showed a significant color changes (P<0.001) which was not clinically acceptable (ΔE>3.3). The two composites did not show any significant difference in discoloration rate. (P>0.05)

  Conclusion: Both micro-hybrid composites(Filtek Z250,Point4) demonstrated color changes which were clinically unacceptable. The imported tea caused more discoloration compared to the Iranian one.